The present invention relates to a power tool having a motor, for driving a power tool, and at least one switching element.
Power tools require diverse switches for switching the motor on and off, and if necessary for performing additional control functions. Usually, one uses for this purpose switches offering an adequate load capability that are sized for the respective rated operational voltage and are capable of switching the sometimes rather high load currents in a range of up to 10 amperes or over. It is understood that switches must be sufficiently robust to ensure that they will not fail, even in professional use where long service times and numerous switching operations are encountered.
As a rule, one therefore uses a single on/off switch only, or at least two on/off switches for controlling the actuation of the motor. In connection with powerful angle sanders, designed as so-called “two-hand” angle sanders, is has been usual, for example, to configure the rear end of the housing as a handle provided with an on/off switch that can be actuated via a pushbutton. In operation, the angle sander is then held by one hand gripping a butt provided on the side of the housing and the other hand gripping the rear handle, while simultaneously actuating the handle pushbutton. When the rear handle is released, the power supply to the motor is interrupted and braking of the angle sander is initiated, if desired.
With a view to improving the ergonomics of the design, it would on principle be desirable to have the possibility to provide switches at any position within the power tool, if possible, and to permit such switches to be actuated very easily and in a force-saving way. Such flexibility does not exist, however, in conventional power tools as due to the requirement that the switches be adequately sizes, the switches have a considerable overall size and can be integrated in the housing at specific points only. In addition, a number of safety rules have to be observed in this connection with the effect that guiding the supply line to a mains switch through a motor housing, for example, is possible only if certain special protective measures are observed, which considerably increases the costs of such an arrangement or even makes its realization impossible.